From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id D8ABDC4338F for ; Fri, 20 Aug 2021 12:40:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C21EA610CA for ; Fri, 20 Aug 2021 12:40:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238215AbhHTMkt (ORCPT ); Fri, 20 Aug 2021 08:40:49 -0400 Received: from wtarreau.pck.nerim.net ([62.212.114.60]:36990 "EHLO 1wt.eu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233303AbhHTMks (ORCPT ); Fri, 20 Aug 2021 08:40:48 -0400 Received: (from willy@localhost) by pcw.home.local (8.15.2/8.15.2/Submit) id 17KCcAgu024415; Fri, 20 Aug 2021 14:38:10 +0200 Date: Fri, 20 Aug 2021 14:38:10 +0200 From: Willy Tarreau To: Jeff Layton Cc: Amir Goldstein , Linus Torvalds , "Eric W. Biederman" , Matthew Wilcox , Andy Lutomirski , David Laight , David Hildenbrand , Linux Kernel Mailing List , Andrew Morton , Thomas Gleixner , Ingo Molnar , Borislav Petkov , "H. Peter Anvin" , Al Viro , Alexey Dobriyan , Steven Rostedt , "Peter Zijlstra (Intel)" , Arnaldo Carvalho de Melo , Mark Rutland , Alexander Shishkin , Jiri Olsa , Namhyung Kim , Petr Mladek , Sergey Senozhatsky , Andy Shevchenko , Rasmus Villemoes , Kees Cook , Greg Ungerer , Geert Uytterhoeven , Mike Rapoport , Vlastimil Babka , Vincenzo Frascino , Chinwen Chang , Michel Lespinasse , Catalin Marinas , Huang Ying , Jann Horn , Feng Tang , Kevin Brodsky , Michael Ellerman , Shawn Anastasio , Steven Price , Nicholas Piggin , Christian Brauner , Jens Axboe , Gabriel Krisman Bertazi , Peter Xu , Suren Baghdasaryan , Shakeel Butt , Marco Elver , Daniel Jordan , Nicolas Viennot , Thomas Cedeno , Collin Fijalkovich , Michal Hocko , Miklos Szeredi , Chengguang Xu , Christian =?iso-8859-1?Q?K=F6nig?= , "linux-unionfs@vger.kernel.org" , Linux API , the arch/x86 maintainers , "" , Linux-MM , Florian Weimer , Michael Kerrisk Subject: Re: Removing Mandatory Locks Message-ID: <20210820123810.GE22171@1wt.eu> References: <87k0kkxbjn.fsf_-_@disp2133> <0c2af732e4e9f74c9d20b09fc4b6cbae40351085.camel@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) Precedence: bulk List-ID: X-Mailing-List: linux-unionfs@vger.kernel.org On Fri, Aug 20, 2021 at 08:27:12AM -0400, Jeff Layton wrote: > I'm fine with any of these approaches if the consensus is that it's too > risky to just remove it. OTOH, I've yet to ever hear of any application > that uses this feature, even in a historical sense. Honestly, I agree. Some have fun of me because I'm often using old stuff, but I don't even remember having used an application that made use of mandatory locking. I remember having enabled it myself in my kernels long ago after discovering its existence in the man pages, just to test it. It doesn't rule out the possibility that it exists somewhere though, but I think that the immediate removal combined with the big fat warning in previous branches should be largely enough to avoid the last minute surprise. Willy